


One Day

by Detective_In_Space



Category: Dangan Ronpa - All Media Types, New Dangan Ronpa V3: Everyone's New Semester of Killing
Genre: Alternate Universe - Coffee Shops & Cafés, Alternate Universe - Modern Setting, Alternate Universe - Non-Despair (Dangan Ronpa), Based off the Love Hotel scene, Detectives, M/M, Phantom Thief AU, Saiouma Exchange
Language: English
Status: Completed
Published: 2018-04-11
Updated: 2018-04-11
Packaged: 2019-04-21 13:40:36
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,237
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14286135
Author URL: https://archiveofourown.org/users/Detective_In_Space/pseuds/Detective_In_Space
Summary: Ouma Kokichi is a barista at Saihara Shuuichi's favorite coffee shop. The two frequently visit one another, but little does Saihara know that Ouma is hiding something. Not only does he have a secret identity, but he is the famous Phantom Thief that Saihara is tasked to capture.(For #18 in the SaiOuma Exchange)





	One Day

**Author's Note:**

> This is for #18 for the SaiOuma exchange. I was your backup Santa. I've never written a Phantom Thief au, but this was really fun to write! I hope you enjoy!

♢♡♤♧

Saihara ran through the dimly lit maze of alleys as he chased after the mysterious figure that jumped from roof to roof of the buildings in front of him. The figure’s dark indigo cloak flew in the wind behind them. After a few moments of being chased, the thief paused as he stood triumphantly on top of a tall building. The bright light of the moon reflected off of a white clown-like mask that covered a majority of the thief’s face. “Nishishi! You know better than this detective! Haven’t you ever heard that it’s not very nice to chase after a poor and innocent soul like me? Don’t make me have to teach you basic manners!” The childish voice claimed. Saihara could almost picture the grin on the other boy’s face as he laughed about him. 

“We both know you’re just joking around. Just get down from there… we can settle this. All you have do is come with me and I can negotiate a smaller punishment.” Saihara explained as he stared up at the other boy. 

“No thanks! I’m perfectly comfortable with where I’m at! Now, if you’ll excuse me, I have some business to take care of! See you later my beloved detective!” The phantom thief exclaimed.

“W-wait! Don’t move or… I’ll be forced to shoot.” However, both of them knew that Saihara would never dare to harm a person. The pistol he shakily held in front of him may have been aimed at the thief, but he would never actually use it. The gun served as a method of intimidation, but the Phantom Thief didn’t believe the bluff for a second. 

“Don’t lie to yourself! As much as I would love to play with you, I seriously have to go. See you later!” The thief declared as he blew a kiss at the detective before disappearing into a violet smoke bomb. Saihara sprung forward to attempt to find where he had vanished to, but he knew he had no chance. Numerous detectives had attempted to catch the notorious Phantom Thief, but none had succeeded. Eventually, the case had been passed down to the younger boy. Now, he had been after the thief for a few months, but he hadn’t been successful with the case yet. Every day he felt as if he was growing closer and closer to catching him, but he was still struggling. He couldn’t even figure out the motive of the thief. He liked to claim that, “He enjoyed the rush of being chased after,” but Saihara thought there was much more to it than that. He’d figure it out soon, but for now, he was still gathering his facts. The only leads he had found were the playing cards the Phantom Thief would leave behind at every run-in. So with that in his mind, Saihara began to look for the card the thief would usually leave behind. After a bit of searching, Saihara came across a small joker that flew down onto a small cardboard box in a dirty alley. It read: 

_ Nishishi, thanks for the fun today, Saihara! I can’t wait to have even more fun another time! I’m still on my quest to steal the Golden-Eyed Sapphire, but don’t worry, I’m getting closer to snatching it! Meet me at the Towa Museum in center field days! I’m sure you know what that means if you call yourself a detective! See you later my beloved! _

_ Sincerely, _

_ Your Favorite Phantom Thief _

The note was written once again in a similar format to the other ones. The thief would always reference some sort of card game in order to lead the detective to his next location. Of course, Saihara was always surprised about why the thief would always give away his next plan beforehand… it was just another thing to add to the board. With a heavy sigh, Saihara headed back to his car he had parked a distance away, before heading back home to the long day of work ahead of him.

 

♢♡♤♧

 

With one hand, Saihara picked up his briefcase almost overflowing with case notes, and on the other hand, the detective grabbed his laptop. He needed to get out of his stuffy office, and the best shot he had at concentrating would be at the local coffee shop, Kuma-Koffee. Every time he would order the same exact thing, a simple black coffee, but that definitely didn’t take the social stress that always came with ordering anything. Once he arrived, he fiddled with the strap of the briefcase handle. To keep his mind busy, he gazed out the front window, focusing his eyes on the constantly moving traffic. However, that was disrupted by a loud, “Nishishi!” Immediately, Saihara snapped out of his daze at the strange laugh coming from the boy behind the counter. He had dark purple hair tied up in a low ponytail and he wore a pair of black glasses. “If you’re done dreaming, I’ll take your order now!” 

The boy’s lilac eyes gazed at him in an expectant way, prompting Saihara to snap out of his state of shock. “S-sorry… I’ll have a small…”

“Black coffee? Sure thing!” The purple haired boy finished as if he was reading the black haired boy’s thoughts. 

Saihara nodded feverishly at this, “H-how did you know I was going to order that?”

“You look like the emo type!” The purple haired boy exclaimed. But once he saw the look of confusion on the detective’s face, he added, “Kidding! You’ve come here at least once a week. Even if I didn’t take orders, I still would’ve noticed the same charming boy coming here to work! Anyways, that’ll be $3.25!” He summed up with a large grin. 

“Right…” Saihara fumbled with the change in his pocket before handing it over to the boy. In return, the barista handed him his coffee. At this, Saihara added, “Thank you. Have a nice day… uh… Ouma?”

“That’s me! See you some other time, Saihara!” Ouma replied happily, reading his name off of the small badge on his jacket. 

With the small encounter over, Saihara looked out of the window with a perplexed expression. There was something… strange… about that barista. He couldn’t quite put a name to it, but he just had a feeling that he had seen him before. Surely he would’ve remembered such an eccentric personality though. He shook his head; the lack of sleep must’ve been getting to him, so with that note in his head, he tapped the black pen against his cheek as he began to concentrate on the case in front of him.

 

♢♡♤♧

 

“Have you happened to see this thief around at all?” Saihara asked a brown haired female who walked down a school hallway with him. He held up a small  _ Wanted _ poster of the famous Phantom Thief. He had grown impatient of waiting until the date the thief had promised, so he resorted to asking students at his school. Through, the hallways might’ve been a poor choice. Around him, other students pushed through the hallways, trying to get to their next period on time, while others chatted loudly to their peers. 

“Sorry… I haven’t seen him at all, but I would ask Kirigiri before coming to any conclusions.” The girl, Naegi Komaru, suggested with a small smile of encouragement. 

“I will… thanks for trying to help though,” Saihara said as he tucked the poster into his pocket. He would ask Kirigiri soon, but for now, he had his heart set on asking some more of his peers. Noticing a small boy with a hood covering his head, Saihara ran over to him. Perhaps he could be of assistance. 

“E-excuse me sir, but do you mind if I ask you a question about the Phantom Thief?” Saihara asked as he walked next to the strange boy, who looked strangely familiar. 

“Well, well, well! If it isn’t my favorite customer? It’s a pleasure to see you somewhere else than in that stuffy coffee shop!” Ouma exclaimed with a grin on his face. However, his attempt to get the detective riled up ultimately failed when all the golden-eyed boy did was stare back at him. “Hello? Is there something on my face? I mean, I know I look quite handsome, but this is just getting creepy!”

This seemed to do the trick as Saihara snapped out of whatever daze he had been trapped in. He shook his head and tried to hide the red blush on his face by pulling down his black cap. “Sorry, it’s just... I’ve never seen you so… casual before. You’re always so professional looking that it’s strange to see you in a school atmosphere.” Saihara explained, and he was right. Instead of wearing a button-up shirt and dress pants, the purple haired boy had an indigo and lilac sweatshirt on, and the hood shielding most of his face. 

“Nishishi, I am quite stunning in whatever I wear! But, was there something you wanted to ask me?” Ouma asked with an innocent look on his face. In fact, it seemed fake, but Saihara pushed that thought aside as he attempted to form understandable words. 

“Well… I was going to ask you if you knew anything about The Phantom Thief, but… I think I would be better off asking my senior, Kirigiri like other students suggested.”

“Well, I think you’re smart enough to solve this case on your own! But… I really don’t know much about him other than his troublesome personality. Someone really ought to catch him soon, and I just know you can do it!” Ouma cheered… genuinely? Saihara couldn’t find a word to describe the tone of the other boy, but nevertheless, that was just what he needed in order to motivate himself. 

“Thank you, Ouma..! I’m going to solve this case…” Saihara paused before sheepishly adding, “And that speech was really what I needed. I’m lucky to have a friend like you.”

“Yeah, yeah, enough with that mushy stuff. Now, go do your thing Mr. Detective.” Saihara nodded as he heard this as he waved goodbye to Ouma. 

In fact, he was so absorbed in what he had planned that he didn’t even notice the way Ouma addressed him. 

 

♢♡♤♧

 

Saihara furiously typed away on his laptop, not bothering to take in any of his other surroundings. He was growing closer and closer to the identity of the mysterious Phantom Thief. Of course, there was still work to do; after all, there was always more work to do. But Saihara knew that the thief’s base was somewhere in this area. Every time, he would lose the thief somewhere in this area. Whether it be on top of a building or a block away, he popped up near the campus of Hope Peak’s University. Some sort of base must’ve been close to where Saihara attended school. Now, he just had to find out where that specific place was. 

“Oh! What’s my beloved Saihara working on today? Still chasing after that rowdy thief?” A cheerful voice exclaimed as arms wrapped around Saihara’s torso. 

The loud voice and intimidate action caused Saihara to yelp out of surprise, “O-ouma… don’t sneak up on me like that.” 

“Does Saihara not like me? I just… I just wanted to say hello to my f-favorite customer on my b-break!” Ouma stuttered as tears began to pool up in his eyes. He sniffled as he tightened his grip on the detective. 

“It’s not that..! I swear! You just surprised me! I enjoy your company, don’t worry.” Saihara frantically explained in order to prevent the other boy from crying. 

“R-really? You really hurt my feelings, so you’ll have to make it up somehow!” Ouma declared as he let go of Saihara to wipe away his tears. 

“And how can I do that?” The black haired detective asked cautiously. He had no idea how extreme Ouma would go with his request, so it was better to be safe than sorry. 

Ouma motioned for Saihara to come close, and as soon as he did so, the purple haired boy whispered, “My beloved has to give me a… kiss!” He tapped his cheek as he grinned mischievously at the golden eyed male. Before any other word could be spoken, Saihara pressed his lips gently to the cheek of the purpled haired barista. He felt the warmth and softness of it for a second before pulling away. The chaste kiss had lasted for what was only a second but for the two boys, it seemed like an eternity. 

“Saihara…” Ouma started as he stared at the detective. His cheeks were dusted with a light blush, but he quickly willed it away. 

Saihara frantically shoved random papers into his bad, before running out of the cafe, “I-I’m sorry Ouma… I just have to g-go!” Ouma barely had any time to react as he simply kept his eyes on the still warm coffee cup the other black-haired boy had forgotten. He hadn’t been serious about that kiss, but he didn’t necessarily hate it… screw that, he hated it. He hated the warm feeling in his chest that was threatening to burst out of his chest. He hated the way a light pink blush appeared on his face. He hated the way the stupid detective made him feel. At least, those were the things he kept telling himself. No matter what happened, he kept reminding himself of one thing.  _ He would never be so foolish to fall in love, especially with the person who was tasked with capturing his other identity. _ He simply brushed away all the warm thoughts by taking a damp rag out of his apron and wiping down the table. He adjusted his glasses before taking his normal place behind the coffee shop counter. Now, he had more important activities to think about. Such as how he was going to deal with the ‘theft’ he had planned for a couple hours later. 

 

♢♡♤♧

 

“Give it up, Phantom Thief. I have you cornered, so just tell me where you hid the Sapphire.” Saihara stated as he pointed a flashlight at the thief adorned in a clown-like mask. Despite the room almost being pitch black, the mask shone directly at Saihara. 

“Really? Are you playing that card on me? And here I was thinking that you learned a bit more after all of our encounters! What a disappointment!”

Saihara shook his head at this, “Stop trying to get into my head. There is nowhere for you to run to this time. So just give it back to the museum!”

“Silly detective! I don’t even have it! If you look back to the display, it’s right where it should be!” The thief claimed. Saihara’s own curiosity grabbed ahold of him as he turned his head to see the sapphire right in its place. 

“W-wait? What? Why would you put it back after going through all the trouble to get it?” Saihara asked as he turned his head to… nothing. The thief had slipped away once again…He had slipped away to the escape exit, in a matter of seconds. 

“Well as much as I love chatting, I have to go! Toodles!” The Phantom Thief exclaimed as he ran out of the museum, leaving Saihara alone once again. 

 

♢♡♤♧

 

“Still working on that case, huh?” Ouma asked as he slid into the chair across from Saihara, who was still typing away on his laptop, like always. 

Saihara nodded as he looked up at the purple haired boy, “I’m getting closer, but it’s always as if I’m one step behind this thief. I’ll solve one part of this case, but then I’ll be introduced to another mystery to solve.”

“You’ll catch him eventually, Saihara. You’ve solved every case you’ve ever received. Even if it takes a while to do so, you’ll get him eventually.” Ouma encouraged as he smiled at the detective. 

Saihara stared at him with shock, as if he had never received compliments like those before. His surprised expression soon morphed into a smile as he said, “Thanks… I really needed that.”

“Of course you did! Only I can make Saihara so happy, nishishi!” Ouma claimed. 

“W-well… I mean… you’re too kind to me. I wish there was some way I could pay you back for all you’ve done for me.” Saihara explained with a small blush on his face. 

“You’ve done more than enough! Seeing you in a good mood is enough for me, so don’t worry at all!” Ouma replied as he stood up. “I gotta go work, see you later, detective!” Ouma waved as he skipped away from the table. 

 

♢♡♤♧

 

“Hm? What’s this? Is this a proposal for me? I didn’t know you felt this way about me!” Ouma exaggerated as he looked down at the gift in his hands. 

Saihara shook his head, “You’ve done so much for me… it’s the only way I could repay you. Besides, it’s really not too big of a deal… it’s just a small gift.” 

“A lifetime supply of Grape Panta is the way to my heart though!” Ouma argued as he pulled the 8 pack of bottles close to his chest. 

“Ouma, it’s 8 bottles. I know for a fact that you’ll drink all of that in less than a week.” Saihara deadpanned. The drink had been on sale, and he remembered Ouma once telling him that it was his favorite drink. 

“Still! It’s the best gift I’ve ever received! Ever! Love you, Saihara!” Ouma cheered. 

“W-what? You can’t just say things like that..!” Saihara protested… well, he attempted to protest. His face was covered with a dark red blush and he refused to look the other boy in the eyes. 

“I just did, nishishi! Well, see you later!” Ouma declared as he skipped into the backroom, leaving a flustered Saihara staring at the doorway. It hadn’t meant much… Ouma just liked to tease him in different ways. He closed his eyes and took a deep breath. That’s all it was, a joke. He turned away and collected his materials before stepping out of the small cafe.

 

♢♡♤♧

 

Saihara took a deep breath as he climbed onto the roof using a ladder. He lost The Phantom Thief every time he chased him from the ground, so it was time to try something new. Instead of staying on the streets, he would use the thief’s own highway, the roofs of buildings. However, saying he was terrified would be the understatement of the decade. Almost anyone would be terrified to climb up on a roof of a building, but to play a game similar to tag on one? Well, that would scare the living shit out of the average person. But Saihara couldn’t let the famous thief see him in a vulnerable state, so he put on a brave face and stared directly at the mocking clown mask. “Your time is up. You can’t run away from me this time, Phantom Thief.” 

“Oh, please! I have plenty of time! In fact, it’s only about… one in the morning and that means I still have a long time left until this day is over!” The thief declared as he drew out every syllable. “And good luck catching me. I have tons of experience when it comes to parkour, so good luck catching me! But hey, if you do… I’ll gladly leave with my beloved!” With that final note, he turned away and began to run from the detective. 

Almost immediately, Saihara took after him. He held one hand on the side of his belt where a small gun rested. He would only use it in the most drastic of scenarios, but he had to be prepared for when that moment would arrive. No. That moment would never arrive. He had to stay calm and think rationally. He brushed that thought aside and concentrating on keeping his footsteps steady and collected. However, one wrong move completely ruined everything. He had prepared himself to jump onto the next building, but he had just barely missed it, his foot slipping on the edge of the brick building. He cursed to himself as he gripped onto the edge. Below him, cars drove quickly across the semi-busy street, and he was too high up to land safely. In summary, he was doomed. No scream nor shout could save him from his doom; all he could do was anticipate the moment when his strength would disappear, which would be soon based on his lack of upper body strength. 

He was about to lose all hope until a familiar figure stood above him, reaching out a hand. Without much choice, Saihara grabbed ahold of the hand and felt himself slowly being pulled back onto the roof of the building. He was in such a state of shock that he didn’t care what he was doing. He latched onto the person who had saved him and cried into their clothes. He had almost died, and he most definitely wasn’t in a state to get back up and continue his game of chase. He felt his hat lift off of his head, and at this, he mumbled words of protest. However, this ended as he felt soft fingers come through his hair. Their fingers danced through the tangles of his short hair and he leaned into their touch. 

After a while of the repeated activity, Saihara pulled away to see who his savior was, but he was shocked as he saw shining lilac eyes staring back at him. He almost gasped as he looked more and more at the person who was so familiar to him. The messy purple hair. The pale and almost white skin. 

  
_“Ouma… this can’t be you… please tell me it isn’t!”_

 

“Nishishi, they don’t call me the master of lies for no reason! So say, my beloved detective, are you shocked?” Ouma replied with a grin. 

“Stop… stop kidding with me,  _ Kokichi. _ You’re the nicest person I know, you can’t be… a criminal.” Saihara said through breaths of panic. 

“Your view of niceness must be pretty twisted! I’m a criminal! After all, I was the person who stole the gem most valuable to you, so there is no denying it!” Ouma claimed as he stood up, “Come on and get up now. You’ve been chasing me for months, and I’m giving myself up. This is a once in a lifetime opportunity, so you better take it!”

“I… can’t just do this to you. You’re in college… and if I let you go, then I’ll just make something up! It’ll be alright for you!” Saihara exclaimed. He could make things right for the both of them. He could let Ouma finish college and help him find a successful job and maybe help him find a place to settle down. There was so much left unfinished, and he didn’t want Ouma to rot away in his cell for his entire life. 

“Saihara! You can’t risk your future for me. Trust me, I’ll survive whatever is thrown at me, so don’t worry about little ol’ me!” Ouma insisted as he motioned for Saihara to handcuff him. 

“I… I promise to make sure that you’re given a light punishment. You may have given the police force quite a chase, but really… you never actually stole anything.” Saihara said as he led Ouma to his police car. Perhaps one day, everything could turn for better for the pair. One day, everything would turn back around. One day… 

 

♢♡♤♧

 

_ A year and a half later… _

 

“Awe! Were you waiting for me? Just for me?” Ouma pestered as he wrapped Saihara in a hug. 

“Well… I thought we could do something… just the two of us?” Saihara said as he dodged the question. The truth was that he had waited over an hour for Ouma to be done with his community work. Since he hadn’t actually stolen anything, he got away with a punishment of two years of community service, for all the trouble he had caused for the police. 

“Really? You know I have high expectations for things like this!” Ouma replied, though his face was muffled by Saihara’s clothes. 

“Of course… only the best for you…  _ Kokichi _ . Now, what do you think of going out for dinner and watching a movie together?” Saihara asked.

“That’ll do… but only if I get to pick the movie! You suck at that job, so it’s only fitting for someone like me!” Ouma claimed. 

“I know… I know…” Saihara murmured as he grabbed ahold of the small hand, tugging the shorter boy away.

Before leaving the park, Ouma stopped suddenly before motioning for Saihara to lean down. “One last thing…” He muttered, “You have to close your eyes though.” Saihara compiled, a bit worried about what would happen. But before he knew it, a gentle pressure was on his cheek for a couple of seconds, before he was pulled away once again. “Slowpoke Shuuichi! Hurry up!” Saihara was in a daze as he followed him. This way the day… with Ouma, he could finally be happy, and there was no way that was going to change. He grinned as he looked at the cheerful purple haired boy. 

_ He would never give this up. _

_ He had almost lost him once, and he never would let go again. So with that thought in his head, he let himself be pulled along by Ouma, the thief who had stolen his heart.  _

**Author's Note:**

> Notes: 
> 
> I don't work in the field of crime, so I do not know the correct punishments. I simply created a punishment that would fit in with the end of the story. 
> 
> In the end, yes, Ouma and Saihara are dating. I didn't write what occurred in the span of those 18 months, but I did hint towards romantic feelings in the piece. However, I can tell you that it did fully take 18 months for them to realize their feelings for one another. Saihara is pretty dense when it comes to anything romantic, and I headcanon Ouma as being afraid of love, as he sees it as a weakness. 
> 
> I love to rp or just talk, so if anyone would like, you can contact me @detective-in-space on Tumblr or @✧Ace-In-Space✧ #4602 on Discord.


End file.
